I'm at the end of my patience for this setup... Last year, I had good success that was both solid in performance (for the gfx card) and in stability for six months. Then it suddenly stopped working. Since then I have tried every option I can think of and have been utterly unable to get any gaming system stability (for the same games even!)

Any time the eGPU system is given "heavy load" I get a black-screen freeze. It is either instant (using the GTX560TI or after 5-30 minutes w/the GT240).

Here are the scenarios and new components I've bought and tested, in every possible combination:
1. Soldered a bypass to the PE4H fuse
2. New PSUs (250W, 300W and 600W); 600W was the new one
3. New PE4L (had a PE4H)
4. Three different mHDMI cables
5. Many different NVidia drivers, including optimus
6. New video card, Geforce GTX560TI (had GeForce GT240)

A few eccentricities:
* did not replace the EC2C
* PCI reallocation pre-boot is only needed for the GT240
* the GTX560TI only works if I boot with it plugged in (no pci realloc script is necessary...)

Any advice or similar experiences would be *greatly* appreciated.

--
Update 6/14:
* After reading the last hundred pages or so of this thread (totally caught up now!) I am buying yet another PSU. It seems pretty likely now, others have had similar stories, that the blackscreening is insufficient power. The (cheap) Diablotek 600W is going back in exchange for a Corsair 430W 80plus AND a 500W (the latter is incase I end up buying additional components for an entire desktop soonish). I am dead serious about solidifying the PSU in the eGPU equation.
* Nando also suggested swapping HDMI cable but I'm using DVI - this might help someone else though.

I will be doing a DIY ViDock in the future, I am thinking a GTS 450, for my ThinkPad T400. I was settled on a PE4L, until I saw that the T400 is capable of combining two PCI ports to get x2 bandwidth instead of x1, with the PE4H. Is that correct?

If so, I have another question. What PSU do I need for the PE4H and the GTS 450? I don't want an ATX, I want a power brick to keep it tidy and somewhat portable. Can you maybe give me a link to an eBay listing or the like for the UK? (where I live) If I am not mistaken the GTS 450 needs a 120W PSU, but I have no idea as far as the diameter of the plug or the voltage.

How will I connect the PSU the 6 pin connector on the card? If I am not mistaken with the PE4L there was some sort of molex connector that required adapter cables. Is it the same for the PE4H? Again if you have a minute could you find me some listings as an example?

Thank you in advance. It is great that you have put so much time and effort into this and I hate to be bothersome, but I just don't want to get the wrong stuff.

The 3dmark06 SM 3.0 value would tell us if Gen2 speed is engaged. What value do you get? Gen 1 without Optimus gets ~ 2000pts.

Now as to x1.Opt not engaging, this is likely due to Optimus setting up only a single "simulated" GT525M via HD3000 link. Can see this by searching your registry for the string "simulate". Need to get it to do that using the GTX460 instead.

The way I'd suggest to do that is disable the GT525M, remove ALL existing NVidia drivers (driver sweeper), remove the GT525M entry from the nvam.inf, reinstall the 275.33 Verde + modded nvam.inf, reboot and hopefully x1.Opt engages.

If that works for you then could try to merge the two simulate registry entries (GT525M/GTX460) to see if can have both entries available, with you manually disabling one of those GPUs for it to work properly.

Click to expand...

Nando,
Removed GT525M from nvam.inf per your instructions still shows GT525M in device manager with same result as before Optimus is not working for GTX460.

Regedit shows that both gt525m and gtx460 seems to have the same values?

Nando,
Removed GT525M from nvam.inf per your instructions still shows GT525M in device manager with same result as before Optimus is not working for GTX460.

Click to expand...

PM sent. Briefly, removing existing drivers then disabling the GT525M (VGA adapter now) prior to loading the Verde driver +nando4 nvam.inf (with the removed GT525M) will mean you'd no longer have a GT525M "simulate" registry entry. You'd only have the GTX460 in which case x1.Opt should engage using the GTX460. As you still currently have a GT525M simulate registry entry please re-do these steps.

Those pictures helped quite a bit too for the cable setup. Do all GTS 450's have the external power connector? And could you direct me to a guide on enabling Optimus? I need to anyways as I want to use my internal LCD primarily. Also, instead of disabling my Switchable Graphics discrete ATI card with the ViDock Setup 1.x tool, can I just disable it in the bios? Or will that not have the same effect?

And finally, anything else I should know before doing this? Thanks again.

Update: Does this apply to me as well?

Only one final dilemma. That arrangement draws 3.3V with the expresscard slot max at 1.3W, which might not provide what is needed OR overdrive the expresscard slot. A better setup would be to connect the AC adapter's USB plug to the PE4L USB plug and route on the PE4L the 5V USB line to the floppy molex 5V input using a small patch wire. The 5V is downregulated to 3.3V on the PE4L. USB can supply 500ma, so there would be 2.5W at least on tap, more if the AC adapter can provide it. A future PE4L 1.6 will supposely provide a jumper to eliminate the need for patching but for now that would be required.

Click to expand...

If it does what will I need to do to overcome this as that adapter does not have a USB plug.